The Jon-E Catalytic Hand Warmer Lot of 2 is a reusable outdoor survival gear perfect for activities like backpacking, hunting, camping, and hiking. Made of durable metal with a silver color, these hand warmers can be activated to reach a temperature of 120°F, providing warmth for up to 12 hours. With a compact size of 3.9 inches in length, 3.5 inches in height, and 0.8 inches in width, these hand warmers are lightweight at 4.2 ounces and easy to carry on the go. The Jon-E brand is known for its quality and effectiveness in keeping hands warm during outdoor adventures.